1. Field of the Invention
The present invention relates to a video game apparatus for executing a video game performed in a three-dimensional virtual space defined by walls and a floor, and also to a medium readable by a computer stored with a video data program for executing the video game.
2. Prior Art
In the field of so-called shooting and role playing games, there is practiced a game of such a type that a three-dimensional virtual space (which is hereinafter termed a "game space") partitioned by a floor and walls is defined, and a story is developed in this game space.
FIG. 8 is a view of one example thereof and illustrates an image displayed on a TV monitor in the course of progression of the game. Referring to FIG. 8, 105 denotes a frame of the image displayed on the TV monitor. 100 denotes a floor of the game space, 101a-101c denote walls of the game space. 102 denotes a door formed in the wall 101c. 103 denotes a weapon (gun) of a protagonist of the game. 104 denotes an antagonist character. Note that the door 102 is openable and closable. When the protagonist opens this door 102, he or she is able to pass through the door 102 and transfer to a game space defined beyond the wall 101c.
According to the game shown in FIG. 8, the story is developed with a game player himself or herself being the protagonist, a viewpoint at the image displayed on the display unit is coincident with a viewpoint of the protagonist in the game space. Accordingly, even if the antagonist character and a power-up item are hidden in the space beyond the wall 101c, there is no rationality to show them as if to be viewed from this side of the wall 101c, and it may be enough to display it just when the protagonist moves beyond the wall 101c.
Such a viewpoint is, however, hard to grasp every aspect of the image in the game space, and it can be therefore considered that the game space is displayed as a bird's-eye view by shifting the viewpoint of the game player up to an obliquely upper position. In this case, it follows that the viewpoint of the game player himself or herself is shifted outwardly of the game space. Hence, a player character whose motion is controlled by the game player and which receives an attack by the antagonist character is displayed in the game space.
When the game space is displayed as the bird's eye view, however, there must be produced an area invisible from the game player which is hidden behind the wall, i.e., the area that can not be displayed on the TV monitor. Then, if the player character enters this invisible area, the game player is unable to confirm a figure of this player character, and it is therefore impossible to operate the player character.
Further, a visual field of the player character is different from a visual field of the game player, i.e., an image of the game space displayed on the TV monitor. Therefore, even the area invisible to the game player because of being hidden behind the wall might be visible from the viewpoint of the player character. In such a case, it is irrational in terms of developing the story of the game that the player character receives a surprise attack from the antagonist character existing in the invisible area, or that the power-up item, etc. existing in the invisible area is overlooked.